1. Field of the Invention
The present invention relates to fastener devices and, more particularly, to a combination tool and fastener.
2. Description of the Prior Art
Fasteners are well known in the art The most common fastener is the standard threaded screw or bolt. The screw or bolt normally has an aperture formed in its head The aperture is engaged by a screwdriver or similar tool having a similarly shaped tip. The aperture on the screw head usually conforms to a "Philips" or "American" type screwdriver.
A major shortcoming in the use of standard screw and screwdriver combinations is the stripping of the screw aperture due to the accidental disengagement of the screwdriver tip from the aperture. This commonly occurs when the screw is tightened excessively or when the screw has been in place for a long period of time and requires great effort in order to be removed. Once the screw head is stripped, it becomes difficult if not impossible to turn the screw.
A further disadvantage of conventional screw assemblies is the difficulty of maintaining the screwdriver in contact within the aperture in the screw head. This is often the result of the stripping of the screw head as previously described. However, this may also result from the inability to maintain the necessary force or balance of force on the screwdriver to keep the screwdriver tip engaged within the aperture of the screw head. This often results when the screw is located so as to make access by the screwdriver difficult.
In an attempt to address this problem, U.S. Pat. No. 4,572,039, issued to Desjardens, discloses an interlocking lock screw and screw driver. The screw head has a specially designed screw channel with entry apertures formed thereon. A specially designed screwdriver blade is provided having guide dimples which match the entry apertures The tool blade dimples are inserted in the apertures and are then slid along the slot to bring the protrusions under the lip of the channel.
The shortcoming of the Desjardins device is that the dimples in the guide blade must be dimensioned to precisely match the apertures in the screw head. The blade must further be moved along the screw head in order to engage under the lip of the channel. Also, no means are provided for securely retaining the screw blade dimples with in the channel.